Sciades passany

Common Name

Passany Sea Catfish

Year Described

Valenciennes, 1840


Dorsal Fin: I, 7
Anal Fin: 17-20
Pectoral Fin: 11-12 rays
Pelvic Fin: 6
Caudal Fin: 13 branched (6 upper, 7 lower)
Gill Rakers: 19-21 (first arch)

Sciades is defined by the combination of the following characters described in Marceniuk & van der Steen (2017): medial fleshy groove absent or present, a tiny fenestra between frontal and lateral ethmoid, posterior cranial fontanel closed, epiooccipital projecting into dorsal shield, occipital process short and tapering posteriorly, nuchal shield small/medium sized and crescent-shaped, vomerine tooth patch present, accessory tooth plates long, and adipose fin as long as anal fin.

Body elongate and robust with a strongly arched back. Head slightly flattened. Greatest body depth at dorsal fin. Snout squared off. Nostrils connected by a conspicuous furrow. Anterior nostril fleshy and posterior covered by a flap. Cephalic shield large and very rough; extends well forward to between eyes with a shallow indent in the middle of the head. Supraoccipital process relatively long but wide at the base, usually with defined keel and tapering posteriorly. Nuchal plate a thick crescent and rough. Mouth almost terminal. Eye relatively large. There are three pairs of barbels (one maxillary and 2 mental) with the maxillary barbel reaching well past the pectoral fin base. A single arched patch of villiform teeth cross maxillary. Vomerine tooth patch present. Accessory patches with no rearward extensions giving the appearance of a two long tooth patches on roof of mouth. Dorsal fin high with a strong serrated spine. Pectoral fins about the same size as dorsal fin with strong, weakly serrated spines. Pelvic and anal fins located far back on body. Adipose fin as long as anal fin. Caudal fin strongly forked. No rakers on rear of gill arches. Body naked.


Dark brown to gray above and on flanks. Belly is abruptly white. Edge of opercle white. Fins dark, some with white edging.


Maximum size to 100cm TL but mostly under 50cm TL.


Found in brackish and marine waters mostly in estuaries and river mouths.


Eastern Venezuela (Gulf of Paria) to northern Brazil (Amazon mouth).


Acero, A. 2002. Ariidae (pp 831-852). In: Carpenter. 2002. The living marine resources of the Western Central Atlantic. Vol. 2: Bony fishes part 1 (Acipenseridae-Grammatidae). FAO Species Identification Guides for Fisheries Purposes. American Society of Ichthyologists and Herpetologists Special Publication No. 5.

Marceniuk, A.P. & van der Steen, P. 2017. Family Ariidae. In: van der Sleen, P., & Albert, J.S. (Eds.). 2017. Field guide to the fishes of the Amazon, Orinoco, and Guianas (Vol. 115). Princeton University Press.

Other Notes

Species of Sciades are distinctive in having a deep groove (furrow) running between the posterior nostrils. Sciades passany is distinctive in it’s genus by having unique tooth patches (two thin horizontal bands) and a shorter snout than the other two Sciades with small nuchal plates (herzbergii, couma). It is nicely intermediate between couma/herzbergii and the shorter snouted parkeri/proops with larger nuchal plates. Gill rakers and pectoral fin rays are also useful in separating Sciades spp.